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Open Access
Article
Publication date: 20 August 2019

Maneebongkot Chaumaroeng and Alessio Panza

The purpose of this paper is to describe the prevalence and factors associated with safe sex behavior among vocational students in Nakhon Ratchasima Province, Thailand…

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Abstract

Purpose

The purpose of this paper is to describe the prevalence and factors associated with safe sex behavior among vocational students in Nakhon Ratchasima Province, Thailand, and to determine the modifying factors listed as socio-demographic characteristic, the level of HIV and sexually transmitted infections’ knowledge, attitude toward reproductive health, and safe sex behavior among vocational students in Nakhon Ratchasima Province, Thailand.

Design/methodology/approach

A cross-sectional descriptive research was conducted from August to October 2018. The multistage stratified sampling, combined with purpose and random sampling, was used to select the participants. One vocational college with the highest number from urban, suburban and rural areas was purposely selected. The sample calculation by using Cochran’s formula, a random sampling by drawing from each college with male and female, was made to obtain the sample size of 355 students. Inclusion criteria included: vocational students, both male and female, aged between 15 and 19 years, resided in the study area, and volunteered to participate. Ethical consent including waiver of the parent’s consent for the participant aged under 18 years for this study was approved by the Institution Review Board for Human Research Ethics, Chulalongkorn University (Certification number JV 823/2561) A self-administered questionnaire was adapted by the principle researcher from the illustrative questionnaire for interview survey with young people (14), and The study of Prevalence of HIV, STD, Drug Use and Risk Behaviors in Adolescents and Young Adults, in Chaing Rai, Thailand (PRAYA) tool (15). All statistical analyses were performed by SPSS version 22.

Findings

The finding revealed that 332 participants were male (57.8 percent) and female (42.2 percent) with an average age of 16.8 years (±1.7). Approximately 60 percent of males and 50 percent of females had experience of sexual intercourse, with their first experience of sexual intercourse at the average age of 15. Most respondents 63.1 percent used a condom and 63.6 percent used contraception in their latest sexual intercourse. About 41.9 percent consumed alcohol and 15 percent reported substance abused. Sexual intercourse among adolescents vocational students were significantly associated with high knowledge of contraception (OR=0.30, 95%CI=0.10–0.82). Positive attitude toward reproductive health had a significant association with sexual intercourse (OR=0.17, 95%CI=0.05–0.58). Sexual intercourse among vocational students were also significant associated with low risk behavior (OR=0.45, 95%CI=0.22–0.91) and high risk behaviors (OR=0.24, 95% CI=0.10–0.59). Contraceptive used in the latest sexual intercourse had a significant association with cues to action (OR=0.43, 95% CI=0.22–0.86).

Research limitations/implications

This study used a self-reported questionnaire to collect information from participants about safe sex behaviors, which might contain bias data and socially desirable answers. The time for collecting data did not match vocational students’ schedule as they were about to have their final exams. An error in this questionnaire was the absence of condom use as one of the contraception methods.

Practical implications

The study showed that both male and female vocational students in Nakhon Ratchasima have a low level of knowledge of HIV, STIs and contraception. This study revealed that females have higher knowledge of all the factors more than males. Males usually received more harassment from peers for being sexually active than females do. Condoms and contraceptive used are inconsistent in all research conducted and have no common ground. Communication related to sex for those who have no partner was poor compared to students who have a partner. The four factors associated with safe sex behaviors should always be considered and surveyed among vocational students, as the study showed that all results vary for a future adolescence study.

Social implications

This research aims at government authorities. The policy makers should include reproductive health and rights in the curriculum. The Ministry of Public health and The Ministry of Education should provide training for the trainer program for teachers concerning safe sex behaviors. For future research, in-depth interview and qualitative study should be used to increase the reliability of the result of the inconsistency of using a condom and contraception. The researcher should do further studies into vocational college semester schedules before collecting data and should spend more time in the college, so the students become more acquainted to the researcher and give a more truthful answer. Moreover, condom use should be added as one of the contraception methods.

Originality/value

This is the first study among vocational students in Nakhon Ratchasima Province which emphasizes specifically on safe sex behaviors and factors related to it. Regarding the population of vocational students, this study covers almost 80 percent of the population. Sensitive questions for sexual activity status and sexually history were answered by a self-administered questionnaire in order to increase sincere answers on their experiences because participants were not shy to disclose their sexual experiences.

Details

Journal of Health Research, vol. 34 no. 1
Type: Research Article
ISSN: 2586-940X

Keywords

Book part
Publication date: 15 August 2002

Richard B. Stewart

Strong versions of the Precautionary Principle (PP) require regulators to prohibit or impose technology controls on activities that pose uncertain risks of possibly…

Abstract

Strong versions of the Precautionary Principle (PP) require regulators to prohibit or impose technology controls on activities that pose uncertain risks of possibly significant environmental harm. This decision rule is conceptually unsound and would diminish social welfare. Uncertainty as such does not justify regulatory precaution. While they should reject PP, regulators should take appropriate account of societal aversion to risks of large harm and the value of obtaining additional information before allowing environmentally risky activities to proceed.

Details

An Introduction to the Law and Economics of Environmental Policy: Issues in Institutional Design
Type: Book
ISBN: 978-0-76230-888-0

Article
Publication date: 20 October 2011

Renkuan Guo, Danni Guo and YanHong Cui

The purpose of this paper is to propose an uncertain regression model with an intrinsic error structure facilitated by an uncertain canonical process.

Abstract

Purpose

The purpose of this paper is to propose an uncertain regression model with an intrinsic error structure facilitated by an uncertain canonical process.

Design/methodology/approach

This model is suitable for dealing with expert's knowledge ranging from small to medium size data of impreciseness. In order to have a rigorous mathematical treatment on the new regression model, this paper establishes a series of new uncertainty concepts sequentially, such as uncertainty joint multivariate distribution, the uncertainty distribution of uncertainty product variables and uncertain covariance and correlation based on the axiomatic uncertainty theoretical foundation. Two examples are given for illustrating a small data regression analysis.

Findings

The uncertain regression model is formulated and the estimation of the model coefficients is developed.

Practical implications

The paper is devoted to a regression model to handle a small amount of data with mathematical rigor.

Originality/value

The theory and the methodology of the uncertain canonical process regression is proposed for the first time. It addresses the practical challenges of small data size modelling.

Article
Publication date: 8 February 2016

Premaratne Samaranayake and Tritos Laosirihongthong

The purpose of this paper is to develop a conceptual framework of integrated supply chain model that can be used to measure, evaluate and monitor operational performance…

1336

Abstract

Purpose

The purpose of this paper is to develop a conceptual framework of integrated supply chain model that can be used to measure, evaluate and monitor operational performance under dynamic and uncertain conditions.

Design/methodology/approach

The research methodology consists of two stages: configuration of a conceptual framework of integrated supply chain model linked with performance measures and illustration of the integrated supply chain model and delivery performance using a case of dairy industry. The integrated supply chain model is based on a unitary structuring technique and forms the basis for measuring and evaluating supply chain performance. Delivery performance with variation of demand (forecast and actual) is monitored using a fuzzy-based decision support system, based on three inputs: capacity utilization (influenced by production disruption), raw materials shortage and quality of dairy products.

Findings

Integration of supply chain components (materials, resources, operations, activities, suppliers, etc.) of key processes using unitary structuring approach enables information integration in real time for performance evaluation and monitoring in complex supply chain situations. In addition, real-time performance monitoring is recognized as being of great importance for supply chain management in responding to uncertainties inherent in the operational environment.

Research limitations/implications

Implementation of an integrated model requires maintenance of supply chain components with all necessary data and information in a system environment such as enterprise resource planning.

Practical implications

The integrated model provides decision-makers with an overall view of supply chain components and direct links that need to be maintained for supply chain performance evaluation and monitoring. Wider adaptation and diffusion of the proposed model require further validation of the model and feasibility of implementation, using real-time data and information on selected performance measures.

Originality/value

Integration of supply chain components across supply chain processes directly linked with performance measures is a novel approach for effective supply chain performance evaluation and monitoring in complex supply chains under dynamic and uncertain conditions.

Details

Journal of Modelling in Management, vol. 11 no. 1
Type: Research Article
ISSN: 1746-5664

Keywords

Article
Publication date: 11 November 2021

Nino Martin Paulus, Marina Koelbl and Wolfgang Schaefers

Although many theories aim to explain initial public offering (IPO) underpricing, initial-day returns of US Real Estate Investment Trust (REIT) IPOs remain a “puzzle”. The…

Abstract

Purpose

Although many theories aim to explain initial public offering (IPO) underpricing, initial-day returns of US Real Estate Investment Trust (REIT) IPOs remain a “puzzle”. The literature on REIT IPOs has focused on indirect quantitative proxies for information asymmetries between REITs and investors to determine IPO underpricing. This study, however, proposes textual analysis to exploit the qualitative information, revealed through one of the most important documents during the IPO process – Form S-11 – as a direct measure of information asymmetries.

Design/methodology/approach

This study determines the level of uncertain language in the prospectus, as well as its similarity to recently filed registration statements, to assess whether textual features can solve the underpricing puzzle. It assumes that uncertain language makes it more difficult for potential investors to price the issue and thus increases underpricing. Furthermore, it is hypothesized that a higher similarity to previous filings indicates that the prospectus provides little useful information and thus does not resolve existing information asymmetries, leading to increased underpricing.

Findings

Contrary to expectations, this research does not find a statistically significant association between uncertain language in Form S-11 and initial-day returns. This result is interpreted as suggesting that uncertain language in the prospectus does not reflect the issuer's expectations about the company's future prospects, but rather is necessary because of forecasting difficulties and litigation risk. Analyzing disclosure similarity instead, this study finds a statistically and economically significant impact of qualitative information on initial-day returns. Thus, REIT managers may reduce underpricing by voluntarily providing more information to potential investors in Form S-11.

Practical implications

The results demonstrate that textual analysis can in fact help to explain underpricing of US REIT IPOs, as qualitative information in Forms S-11 decreases information asymmetries between US REIT managers and investors, thus reducing underpricing. Consequently, REIT managers are incentivized to provide as much information as possible to reduce underpricing, while investors could use textual analysis to identify offerings that promise the highest returns.

Originality/value

This is the first study which applies textual analysis to corporate disclosures of US REITs in order to explain IPO underpricing.

Details

Journal of Property Investment & Finance, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1463-578X

Keywords

Article
Publication date: 18 January 2022

Chunxiao Zhang, Xinwang Li, Xiaona Liu, Qiang Li and Yizhou Bai

The purpose of this paper is to focus on an optimizing maintenance policy with repair limit time for a new type of aircraft component, in which the lifetime is assumed to…

Abstract

Purpose

The purpose of this paper is to focus on an optimizing maintenance policy with repair limit time for a new type of aircraft component, in which the lifetime is assumed to be an uncertain variable due to no historical operation data, and the repair time is a random variable that can be described by the experimental data.

Design/methodology/approach

To describe this repair limit time policy over an infinite time horizon, an extended uncertain random renewal reward theorem is firstly proposed based on chance theory, involves uncertain random interarrival times and stochastic rewards. Accordingly, the uncertain random programming model, which minimized the expected maintenance cost rate, is formulated to find the optimal repair limit time.

Findings

A numerical example with sensitivity analysis is provided to illustrate the utility of the proposed policy. It provides a useful reference and guidance for aircraft optimization. For maintainers, it plays an important guiding role in engineering practice.

Originality/value

The proposed uncertain random renewal reward process proved useful for the optimization of maintenance strategy with maintenance limited time for a new type of aircraft components, which provides scientific support for aircraft maintenance decision-making for civil aviation enterprises.

Details

Engineering Computations, vol. 39 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

Content available
Article
Publication date: 21 April 2020

Thi Quynh Mai Pham, Gyei Kark Park and Kyoung-Hoon Choi

The purpose of this paper is to present an integrated model to measure the operational efficiency of the top 40 container ports in the world for a five-year continuous…

1152

Abstract

Purpose

The purpose of this paper is to present an integrated model to measure the operational efficiency of the top 40 container ports in the world for a five-year continuous period using a two-stage uncertainty data envelopment analysis (UDEA) combined with fuzzy C-means clustering method (FCM).

Design/methodology/approach

UDEA model is adopted for measuring the efficiency of container ports to overcome the limitation of the basic model, which is unable to handle uncertain data that are easy to meet in practice. FCM algorithm is implemented to find similar distribution efficiency scores of two stages and the cluster similar efficiency scores of container ports into various groups.

Findings

The combination of the two-stage UDEA model and the FCM algorithm provided a more comprehensive view when evaluating the performance of container ports. The UDEA results show that most of the container ports have reduced their profitability level in the second stage and most of the efficient container ports have turned into inefficient ones because of their small scale.

Originality/value

This paper proposes using the two-stage UDEA model to evaluate port efficiency based on two main aspects of productivity and profitability. Moreover, it combines DEA and FCM algorithms to offer a more comprehensive view when measuring the performance of container ports.

Details

Maritime Business Review, vol. 6 no. 1
Type: Research Article
ISSN: 2397-3757

Keywords

Article
Publication date: 13 June 2016

Lei Wang, Xiaojun Wang and Xiao Li

– The purpose of this paper is to focus on the influences of the uncertain dynamic responses on the reconstruction of loads.

Abstract

Purpose

The purpose of this paper is to focus on the influences of the uncertain dynamic responses on the reconstruction of loads.

Design/methodology/approach

Based on the assumption of unknown-but-bounded (UBB) noise, a time-domain approach to estimate the uncertain time-dependent external loads is presented by combining the inverse system method in modern control theory and interval analysis in interval mathematics. Inspired by the concept of set membership identification in control theory, an interval analysis model of external loads time history, which is indeed a region or feasible set containing all possible loads being consistent with the bounded structural acceleration responses is established and further solved by two interval algorithms.

Findings

Unlike traditional loads identification methods which only give a point estimation, an interval estimation of external loads time history, which is a region containing all the possible loads being consistent with the uncertain structural responses, is determined. The correlation characteristics among the responses of acceleration, velocity, and displacement are also discussed in consideration of the UBB uncertainty.

Originality/value

For one hand, the solution of the inverse problem in original system is transformed to the solution of the direct problem in inverse system; for another, the authors deal with the uncertainty by use of interval analysis method, and the identified interval process, which contains any possible external loads time history being consistent with the bounded structural responses can be approximately obtained.

Article
Publication date: 22 February 2022

Yushi Xie, Lina He, Wei Xiang, Zhenxing Peng, Xinguo Ming and Mark Goh

The purpose of the paper is to develop a hybrid method to prioritize risk factors (RFs) of sustainable supply chain (SSC) considering sustainable customer requirements…

Abstract

Purpose

The purpose of the paper is to develop a hybrid method to prioritize risk factors (RFs) of sustainable supply chain (SSC) considering sustainable customer requirements (CRs) and uncertain evaluation.

Design/methodology/approach

In the proposed method, fuzzy Kano model (FKM) is applied to prioritize sustainable CRs considering customer satisfaction (CS) and objective weight of each CR, the interval-valued intuitionistic fuzzy (IVIF) set theory is integrated with quality function deployment (QFD) to translate the sustainable CRs into RFs of SSC under uncertain environment and the IVIF cross-entropy is used to conduct objective analysis to prioritize RFs. Finally, a case in air-conditioner-manufacturing company is presented to demonstrate the proposed method.

Findings

A case study of SSC risk management, the comparative analysis and associated discussions are conducted to illustrate the feasibility and effectiveness of the proposed method. The results obtained from the case study shows that RF5 (market share reduction) is the most important RF in the SSC. Compared with the existing methods, the proposed method can integrate sustainable CRs into SSC's RFs, handle uncertain information effectively and obtain objective importance of RFs.

Originality/value

Theoretically, the paper develops a customer-oriented model based on the FKM, QFD, IVIF sets and entropy theory to prioritize RFs of SSC under uncertain environment. The model enables to integrate sustainable CRs into RFs managements and is efficient to deal with the subjectivity and conduct objective analysis to prioritize RFs. In practice, the systematic and correct RFs' priorities analysis provides reliable decision support for the managers to take measures to avoid or mitigate the critical RFs.

Article
Publication date: 8 February 2021

Saied Farham-Nia and Alireza Ghaffari-Hadigheh

The aim of this paper is to study the optimal pricing decision in a supply chain with a dual distribution channel in a centralized and decentralized decision-making…

Abstract

Purpose

The aim of this paper is to study the optimal pricing decision in a supply chain with a dual distribution channel in a centralized and decentralized decision-making systems and investigate the economic impact of retail services on pricing behaviors with respect to the power structures.

Design/methodology/approach

To reach the equilibrium behavior of decision-makers, two-stage optimization, the Stackelberg game and the Bertrand–Nash game have been used. Also, to explore the effect of environmental uncertainty on the behavior of decision-maker, demand functions are characterized as an uncertain price dependent, service dependent and channel dependent. Decision parameters are based on experts’ belief degree, in the sense of uncertainty theory initiated by Liu (2007).

Findings

Obtained results reveal that the retail services have a strategic role in the centralized supply chain and the decentralized supply chain with dominant manufacturer, while both the supply chain and the consumer suffer from higher environmental indeterminacy.

Research limitations/implications

This study is based on possible scenarios of dual distribution system only. Further research is recommended to investigate the applicability of the authors framework in different distribution systems.

Practical implications

The study findings are believed to be valuable for supply chains and organizations about to make a strategic decision on price of their good/service.

Originality/value

The paper contributes to the scarce literature on Uncertainty Theory initiated by Liu (2007), and combination of it with Game Theory for pricing in distribution system of supply chains. The study also contributes by investigating impact of non-price competitive factor (level of service) on pricing strategy.

Details

Journal of Modelling in Management, vol. 16 no. 3
Type: Research Article
ISSN: 1746-5664

Keywords

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